1. Field of the Invention
The present invention relates to a controller for a machine tool and a five-axis simultaneous control machine tool controlled thereby. The controller for the machine tool controls a driving motor for a driving axis of the five-axis simultaneous control machine tool having at least a linear axis and a rotational axis.
2. Description of the Prior Art
The machine tool machines a workpiece by controlling a position of each of driving axes by a controller. There happens to generate any quadrant projection caused by an axis reversing of the driving axis, thereby to reduce machining accuracy. It is disclosed in the laid-open patent publication of Tokkaihei 09-81216 that a method reduces the generation of the quadrant projection by deciding an acceleration amount of a backlash in accordance to a machining condition.
Nowadays, a five-axis simultaneous control machine tool is generally improved to higher specifications as shown in the laid-open patent publication of Tokkai 2008-090734.
In this prior five-axis simultaneous control machine tool, it has same reduction of the machining accuracy because of the axis reversing about the driving axis even though a machining track is a straight line. There is known the five-axis simultaneous control machine tool having a rotating axis pivoting a supporting member that supports an endmil as a tool. In machining by the five-axis simultaneous control machine tool pivoting a supporting member supporting a tool, it happens to increase the machining error by the quadrant projection according to a distance from a machining position to a center of the pivoting axis during the pivoting movement of the supporting member when the machine tool has the pivoting axis to pivot the supporting member.